DRY

308

D R Y

i

The term guttce is also applicable to what We ha.ecalled drops.

DROYED ASHLAR, a term used in Scotland for chiseled,or random-tooled ashlar. It is the most inferior kind of hewnwork used in building. It is true, that what is there calledbroached work, is sometimes done without being droved, butin good broached work, the face of the stone should bepreviously droved, and then broached. See the articleMasonry.

DROVED AND BROACHED, a term used in Scotland ,in a more specific manner than that of broached work; seethe preceding word.

DROVED AND STRIPED, work that is first drovedand then striped : the stripes are shallow grooves done witha half or three-quarter inch chisel, about an eighth of an inchdeep, leaving the droved interstices prominent. These kindsof hewn work are not used in England, or at least veryseldom; the work is either regularly tooled, or rubbedsmooth.

DRUIDICAL TEMPLE, stone pillars, arranged in thecircumference of a circle, surmounted with an architraveor entablature, such as Stonehenge . See Celtic Archi-tecture.

DRUM, a cylinder, generally formed of cast-iron, butsometimes of wood, and used on the inclined planes of rail-ways, for receiving the rope which is wound round the sur-face of its periphery, by which movement the waggons areconveyed along the line. Drums are used when the plane isworked by a single rope.

Drum , of the Corinthian and Composite capitals, the solidpart , in the form of a vase, to which foliage, stalks, andcaulicoli are attached. The drum is otherwise called vase.

Drum. See Dome.

DRY-ROT, a highly destructive vegetable disease, affect-ing the timber in the foundations, and other parts of build-ings, in particular soils and situations. It affects the wood,or ligneous parts, in such a manner, as to leave it connectedby nothing but the small hard fibrous portions, which givfe ita curious tremulous appearance, but all of which, whentouched by the hand in the more advanced stages of the dis-ease, readily moulder into a brownish snuff-like dust. It isattended with a peculiar earthy smell, similar to that whichissues from wood fresh dug up after having lain some timein the ground in contact with decaying animal matter, and ismaterially different from that natural sort of decay which takesplace in wood from the presence of wetness.

On the causes of this decay numerous volumes have beenwritten, and equally numerous have been the nostrums for itsprevention or “ cure.” There can be little doubt that, in verymany cases, dry-rot has been engendered by the extremewetness of the timber, caused by its long immersion in thewater, in docks, canals, &c. In our hastily-constructed build-ings, the timber, after having been thus swelled by soakingtoo much beyond its former and its ultimate bulk, is frequentlyframed together while in this wet state, and it cannot be sur-prising that the dry-rot soon appears as a natural consequenceof such unwise proceedings.

It has been said, that moist and warm situations, where thecirculation of the air is impeded, is the generating cause ofthis disease; that the effluvia from timber so diseased, willcarry their effects to the circumjacent timber ; and that anysort of wood, dry as well as damp, so exposed, will be soondestroyed. Timber once infected cannot be restored, and theonly remedy lies in cutting away the diseased parts, to pre-vent the extension of the evil to the remainder; and to effecteven the latter, a free circulation of air must be admitted,and the parts be washed over with a strong solution of iron,

copper, or zinc. Patents have been granted for vario _cations of the latter, as preventives of the dry* 1-0 ^ con gist'tinguishing features of the processes therein empj°y eing in first preparing the timber by a good steaming’^ filingout of the sap, and afterwards injecting, soaking, j. c gait-the timber in a solution of copperas, or other n> e .. yet*The following observations on this important s “-g n gine er3some time since addressed to the editor of the ° >vl‘°and Mechanics’ Encyclopedia,” by Mr. John Gr e S a3 ’ th®yis an experienced and observant shipwright; * n gU gg e5tappear to mark out clearly the true cause of, and then 1 8a very simple remedy for, the evil, it is rightplace in this work. Mr. Gregory says, ‘ Instead ] ea vi n oa piece of timber according to the usual method, J > t r jgl* fthe heart of the tree in the centre, my plan is to s< paftf>down the middle, through the heart, into two e< l p oJ .immediately after the tree is felled ; and my re ^f° yI will now endeavour to explain, to the best ot <j oe3 jifl >It is, I believe, a well-known fact, that a t T ee 0 f th® ^literally speaking, die on receiving the final stroke ve get ate ^but that it continues for a long period afterward® cea se "though less vigorously. At length, however, . e . ceS of 'to circulate, the pores become closed, and the J u ^ fo'! n stree thus shut up undergo decomposition, and lay w j , 0 ot edation of dry-rot. It is well known, that a 1118 Jp eC t t*f,in a full habit of body, soon decays ; the same aD , eplace in a tree full of sap, unless we adopt the ® h uD,!, g9with respect to it as the Egyptians practised wi ^ prof^body, viz., that of depriving it of all moisture, w evcr )ast | J’“ swould give to our timber a durability abnos lV [jjcb ' jMy mind has been long impressed with this i^ e

wbi?\>

been confirmed by my having recently noticed,ot the timbers, in a very ancient public building) ■ ,

een sawn originally in the manner I haveperfectly sound, although they had withstood the d, ‘f lbel -shand of time for seven hundred years; while otbex^ ^tl/

ihe same buiidjnn- , ~-years; wuac-

s q oared out with°thet had not been s ° eat > but Kt#'“*■ That thTZ l heart in tb e centre, were pe^f^g

closed in the heart caused ^

opportunities of a■ t >e tlm ber, I have had ‘> e .

rience in the ren . S . ervin £ during my long practical f

"I** ««h ■ l “> i "^'“ i? ““* ° f ;

uniformly notifW .Sp? n * It,eai ot timber are employ 6 "’ t fre

run fore and aft i, • tbat the decay commences j

*> dose together’? owin S to the timber* bewgfag

thus enclosed in th« t, 6 ^ ee ^ s or ^ ower en< ^ s ‘ l bee -

no access to thp aw . earts °* the timbers, and the u ! r ' r& bf

i have sometimes wi. ' ,s tiis necessary con ^

Jn such a rotten stnt tnessed these parts of the frameworkmen to a hpo % as to ^ ave been justly coi»p al ! .

midshSs t W P h° ffflanure - Secotdl/those

planks, nre^nof « * £. ave been bored off with tbestance of the which I attribute to the

the destructive 3 of *

frequently J,anni s being thereby carried off- ^ . a refound, on break t lat f b e floor-timbers of an °, v iver 6’ hieakmg up, to be nearly as sound as t % )gt0

— caems to be .),(>«>)

-■ ver L be>

th> s

when first put in.the effect of the salt water, which consta

up, to be nearly as sow— Q ,

Their preservation seems to

water, which constantly laves•-i.iorl: or 1*

the effect ot the salt water, wmcn um—»— ■ j . or *■causing them to become, in a manner, pickled» vv -oo'

that the salt entering into the composition ot e yt~ .. nre ther Q°j *

in®/

nd)

yea 1 '

destructive effects of its natural juices are t0 the \Fourthly, the planks in the bottom, near ^.,;is aretake the infection first; and where the tree' ‘ a 1

the disease rapidly extends endways ot 1 t j ie bethose parts of the deck-planks that lie W P

pel’